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---
title: Naval_Doctrine
---
::: mw-parser-output
**Naval Doctrine**

Your Naval Doctrine influences your naval combat, it determines what
kind of fleet you\'ll want to build and how you\'ll want to use it.

::: {#toc .toc aria-labelledby="mw-toc-heading" role="navigation"}
::: {.toctitle dir="ltr" lang="en"}
## Contents {#mw-toc-heading}

[ ]{.toctogglespan}
:::

-   [[ 1 ]{.tocnumber} [ Doctrine Overview
    ]{.toctext}](#Doctrine_Overview)
-   [[ 2 ]{.tocnumber} [ Doctrine Summaries
    ]{.toctext}](#Doctrine_Summaries)
    -   [[ 2.1 ]{.tocnumber} [ Sealane Interdiction
        ]{.toctext}](#Sealane_Interdiction)
    -   [[ 2.2 ]{.tocnumber} [ Fleet In Being
        ]{.toctext}](#Fleet_In_Being)
    -   [[ 2.3 ]{.tocnumber} [ Base Strike ]{.toctext}](#Base_Strike)
-   [[ 3 ]{.tocnumber} [ Abandoning Your Doctrine
    ]{.toctext}](#Abandoning_Your_Doctrine)
    -   [[ 3.1 ]{.tocnumber} [ Germany ]{.toctext}](#Germany)
    -   [[ 3.2 ]{.tocnumber} [ Italy ]{.toctext}](#Italy)
    -   [[ 3.3 ]{.tocnumber} [ UK ]{.toctext}](#UK)
-   [[ 4 ]{.tocnumber} [ Doctrine Trees in Depth
    ]{.toctext}](#Doctrine_Trees_in_Depth)
    -   [[ 4.1 ]{.tocnumber} [ Sealane Interdiction
        ]{.toctext}](#Sealane_Interdiction_2)
    -   [[ 4.2 ]{.tocnumber} [ Fleet In Being
        ]{.toctext}](#Fleet_In_Being_2)
    -   [[ 4.3 ]{.tocnumber} [ Base Strike ]{.toctext}](#Base_Strike_2)
:::

## [ Doctrine Overview ]{#Doctrine_Overview .mw-headline}

Naval Doctrine effects:

-   Organisation and Morale values.
-   Convoy Raiding and Convoy Escort efficiency.
-   ASW efficiency.
-   CV strike efficiency.
-   [Positioning](/wiki/Positioning "Positioning") . This value is
    critically important, check out the Naval Primer for further
    explanation.

There are 3 Naval Doctrine trees available, and they are in no way
equal.

-   Germany practices Sealane Interdiction (SLI).
-   Britain, France, Italy, Australia, Canada, Netherlands, South Africa
    and the SU starts with Fleet In Being (FIB).
-   The US and Japan go for Base Strike (BS\...).

While each tech tree excels in a certain area, it is quite clear that BS
\> FIB \> SLI whatever you want to do. Gaining naval superiority is
always better than working around it.

## [ Doctrine Summaries ]{#Doctrine_Summaries .mw-headline}

### [ [Sealane Interdiction](/wiki/Sealane_Interdiction "Sealane Interdiction") ]{#Sealane_Interdiction .mw-headline}

SLI is the least popular doctrine, with Germany as its sole worshiper.
It emphasises convoy raiding with U-boats, basically weakening the naval
might of an enemy you\'re never going to surpass. It is the shortest
tree out of the three, ending in 1942 and gaining most of its bonuses by
1940, when it even outshines the other two doctrines for a brief period.
SLI offers the best morale, the best SS positioning, and the best convoy
raiding efficiency.

A quick note about raiding and U-boats: Raiding won\'t make Britain run
out of resources because of the pre-war buildup. It\'s more than capable
of stopping supply convoys though, thereby hampering their ability to
wage land wars overseas. DD seriously crippled the U-boat\'s sea attack
rating, introduced sonar and ASW upgrades for ships, and added the
U-boatkiller CVL into the mix. U-boats are still the best option for
convoy raiding, but they will not destroy the enemy fleet like in HoI2.
You should abandon this tree if you\'re going for naval supremacy.

### [ [Fleet In Being](/wiki/Fleet_In_Being "Fleet In Being") ]{#Fleet_In_Being .mw-headline}

FIB focuses on naval supremacy through (non CV) capital ships, and helps
to maintain your colonial empire. It has the best BB and BC positioning
scores, the best organisation, and the best convoy escort and ASW
ratings. It will also gain convoy the escort bonus slightly earlier than
BS, and it\'s a nice counter to SLI. This tree ends in 1944.

### [ [Base Strike](/wiki/Base_Strike "Base Strike") ]{#Base_Strike .mw-headline}

Base Strike is the longest and most powerful of the three tech trees. It
focuses on winning naval battles with the help of Carriers. It offers
the best CV and DD positioning by far, and the best CV strike
efficiency. It also has a convoy raiding bonus (although weaker than
SLI), and the convoy escort + ASW bonus (although slightly weaker than
FIB). The tree ends in 1947 (or 1952 of you consider the semi unrelated
amphibious bonus). It will always have the best CV and DD positioning
bonus. CVs are the key to naval victory, and therefore this doctrine
tree is the key to naval supremacy.

Note that even though Carriers receive snow, rain and misc bonuses, this
will not make them effective in bad weather. They are still sitting
ducks when it\'s snowing.

## [ Abandoning Your Doctrine ]{#Abandoning_Your_Doctrine .mw-headline}

It is usually best for you to stay where you are. But if you decide
switch, you should obviously switch to Base Strike.

### [ Germany ]{#Germany .mw-headline}

The early bonus of SLI allows you to attempt an early Seelöve at the
start of the war, if you start building ships early. This is your only
chance though, and it\'s fate will most likely decide your multiplayer
match. Or you could focus on land as you should, and raid Allied
commerce with U-boats (or even ignore your navy altogether). Your tech
teams are well suited to research SLI, but not BS. You will be dependant
on Japanese blueprints to get far in the BS tree, and you\'ll have to
neglect some of your precious air/land research. I wouldn\'t bother
abandoning, as it\'s the Soviet invasion that decides most games anyway.
You will have to give up on early naval operations, and four techs you
start with to go for Base Strike\...

### [ Italy ]{#Italy .mw-headline}

Your tech teams are disastrous, but their expertises are somewhat useful
in FIB. Not quite so in BS. You start with a sizeable non CV fleet, and
FIB goes well with that. Chances are your sea battle will be over long
before you could go anywhere deep into BS or ally with Japan for
blueprints. Abandoning your two starting techs will probably hurt more
than you could gain in the long run.

### [ UK ]{#UK .mw-headline}

You start with an awesome fleet of battleships, and you\'re not likely
to lose a naval battle against Germany or Italy anyway. The ASW and
escorting bonus could help a lot too. The UK gets a nice BS tech team in
1943, and can hope to get blueprints from the US as well. You should
consider switching if you\'re planning to move against the US later in
the game, or maybe if a super Japan emerges through some weird twist of
fate.

## [ Doctrine Trees in Depth ]{#Doctrine_Trees_in_Depth .mw-headline}

### [ Sealane Interdiction ]{#Sealane_Interdiction_2 .mw-headline}

------ ----- -------- --------- -------- ----------- ----- -------- ---- ------- ------- ---- ---- ----
  Year   Org   Morale   Raiding   Escort   CV Strike   ASW   SS       CV   BB      BC      CA   CL   DD
  1939   20    20       25        0        0           0     30(5)    0    10      10      20   20   15
  1940   50    70       50        0        10          0     40(10)   5    30(5)   30(5)   30   30   20
  1942   50    70       50        0        10          0     50(15)   5    30(5)   30(5)   30   30   20
  ------ ----- -------- --------- -------- ----------- ----- -------- ---- ------- ------- ---- ---- ----

### [ Fleet In Being ]{#Fleet_In_Being_2 .mw-headline}

------ ----- -------- --------- -------- ----------- ----- ---- -------- -------- -------- ---- ---- -------
  Year   Org   Morale   Raiding   Escort   CV Strike   ASW   SS   CV       BB       BC       CA   CL   DD
  1939   20    10       0         10       10          10    0    5        30(10)   30(10)   20   20   15
  1940   35    20       10        10       20          10    10   15       40(10)   40(10)   35   35   25
  1943   50    30       10        50       20          50    10   15       40(10)   40(10)   35   35   45(5)
  1944   70    50       10        50       30          50    10   25(10)   50(10)   50(10)   50   50   50(5)
  ------ ----- -------- --------- -------- ----------- ----- ---- -------- -------- -------- ---- ---- -------

### [ Base Strike ]{#Base_Strike_2 .mw-headline}

------ ----- -------- --------- -------- ----------- ----- -------- -------- -------- -------- ---- ---- -------
  Year   Org   Morale   Raiding   Escort   CV Strike   ASW   SS       CV       BB       BC       CA   CL   DD
  1939   15    20       0         0        20          0     0        15       10       10       15   15   15
  1941   35    40       25        10       20          10    30(10)   30       20(5)    20(5)    25   25   30
  1943   50    60       25        40       35          40    30(10)   40(5)    30(10)   30(10)   40   40   60
  1944   50    60       25        40       45          40    30(10)   55(10)   30(10)   30(10)   50   50   65(5)
  1947   50    60       25        40       45          40    30(10)   65(10)   30(10)   30(10)   50   50   65(5)
  ------ ----- -------- --------- -------- ----------- ----- -------- -------- -------- -------- ---- ---- -------
:::